


Copper & Tellurium

by Nyarm



Category: Undertale (Video Game)
Genre: M/M, Platonic Relationships, Rating will probably go up, Romantic Fluff, Science Boyfriends, W. D. Gaster is not related to Skelebros, it'll vary
Language: English
Status: In-Progress
Published: 2017-07-16
Updated: 2017-07-27
Packaged: 2018-12-02 17:35:19
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 3,350
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11514159
Author URL: https://archiveofourown.org/users/Nyarm/pseuds/Nyarm
Summary: CuTe Sanster oneshots!I really love this ship, so I'll be writing a bunch for it. Requests welcome!





	1. Take a break!

**Author's Note:**

> okay so
> 
> their relationship will probably be different every chapter, but for the most part it will be unrelated coworkers or boss/employee. i'll tag smut chapters in the title, but for now everything is nice and sfw. C:

Sans plunked a cup of coffee down onto Gaster’s desk, seemingly without the other noticing. It was the seventh one today. Despite his irritation at being reduced to an errand boy at times, he did feel concerned about the way his boss had been obsessing over the same problem all day. They’d hit an unexpected bump in the road with their work and, even after the others had left, the good doctor had continued to labor over it. He’d gotten farther, but he’d been stuck on a particular problem for a while. A long while. Sans, being his personal assistant and being foolish enough to have put his hours down as flexible on his resume, had to stay and help. 

“Hey, doc… maybe you should take a break. Call it a day,” Sans offered, sidling up to the desk’s edge. If Gaster went home, he’d get to go home, too. 

“No.” And there it was. He should probably go busy himself with something productive like more data input instead of hanging around his boss’ desk, but that sounded like work. Boring work. Gaster was usually up for some mindless chatter, if Sans approached him the right way, but so far, every single attempt to strike up conversation had been thus rebuffed. He’d tried a bit of mindless prattling to get the guy away from his work, but the other was not at all keen on conversing at the moment.

“Are you sure you don’t want any help?” This question, too, had been rejected a few times. Sans hoped his frustration hadn’t seeped into his voice at all. It would go faster if he helped, he was sure. At the very least, it’d be better than sitting around and waiting until his boss needed more caffeine. 

“No, Sans. I can do this by myself. Besides, this work isn’t your specialty.” Gaster glanced up at him, tired eyes leveling an disdainful stare onto him. While that was true (Sans was more a theoretical guy, not the applied type), he was familiar enough with this work to do it. And do it well. As he had done all day, but, for some reason, he’d been barred from helping a few hours after the others left. For the past couple of hours he had been doing nothing but data entry and he had never felt so bored in his life. He’d thought getting a job as assistant to the Royal Scientist would have been an end to years and years of intern duty. Though he had thought the same thing about graduation. So.

“I’m sure it’d at least go faster if I could lend you a hand.”

“I have a sufficient amount of hands, Sans. Can’t you just go get some more coffee? That’d be helpful.” Sans repressed a sigh as he slid over the cup he had just fetched.

“Oh.” At least Gaster had the decency to look surprised at its presence before his face fell back into its well-worn Disapproving Neutral. The man had a bad tendency to get sucked into his work fairly easily. Sans couldn’t help but be a little worried at the glaring lack of awareness.

“Do you even know what time it is?”

“Of course, I do. It’s three.”

“Heh, so close. It’s three threes plus two. Eleven.” Gaster scowled at him. Sans nonchalantly grinned back.

“Well, whatever. I’ll stay here all night if I must. I know I can solve this.” The doctor glanced back down at his papers, filled from margin to margin with his strange script. Sans really couldn’t understand his weird need to get things done as quickly as possible. As a fine connoisseur of the art of putting things off, he couldn’t empathize.

“You can pick it up again tomorrow.”

“I don’t need to, I can finish this today.” Gaster’s words sounded forceful, like he was really talking to himself. 

“Well, tomorrow you’ll have the rest of the team to help you out. It’d just make more sense to do it then. It’ll be tomorrow soon, anyways.” 

“I don’t need help.” Sans had to restrain himself from rolling his eye lights. Gaster could be so petulant sometimes. 

“If it’s taking you so long, maybe you do need some help.” He must’ve struck a nerve or something, because the doctor looked kind of angry. Was that what this was about? Sans was losing sleep because Gaster was too prideful to admit defeat for a day? He should probably be a bit more sympathetic, but just because the guy was so insecure about his competency didn’t mean he had to take it out on Sans. It wasn’t the first time his feelings had caused Sans some trouble.

“I’m just doing a thorough job! If I was as sloppy in my work as you are, I would’ve been done by now.” He sounded defensive, which took a lot of the intended sting off of his lame jab at Sans. He must’ve worked himself up into a tizzy over this, judging by the way he was glaring holes into his paper. The skeleton felt a little pity seep through his frustration; the doc seemed genuinely frustrated. It was fine to be driven, but Gaster seemed to take things too personally sometimes. He always felt the need to live up to his own impossible expectations. Usually this attitude was great for the preciseness of their work, but as soon as he’d hit a bump in the smooth road of their progress and couldn’t meet said expectations? Well, this happened. Poor guy.

“Just because you’re having trouble with one problem doesn’t mean you aren’t a really smart guy, doc.” Sans flapped a hand at his papers.

“I shouldn’t be having trouble.” He sounded a little sullen, still. Gaster propped his chin up on his hand and breathed out. He seemed stressed. 

“Everyone has trouble sometimes.” 

“I suppose.” Pouty as ever, Gaster slid out of his seat and began neatly stacking his papers up. Success. Sans rubbed at his eye sockets. Being a good friend was incredibly hard work.

**Notes for the Chapter:**

> please tell me how i did! 
> 
> also this chapter may seem pretty platonic, but let me tell you it is written through the eyes of a shipper.
> 
> hit me up on tumblr! pixie-pier.tumblr.com


	2. Movie Night

**Notes for the Chapter:**

> so this is for a hurt/comfort request! 
> 
> warning: vague spoilers for madoka magica

It was the end of the week, which, of course, meant movie night. Although the weekly nature of movie night sometimes necessitated repeated viewings of films, Sans had been lucky enough to filch a lone box set of some show from the trash heaps in Waterfall. It was wet and soggy and more than a little dirty when he’d picked it up, but, hey, what wasn’t nasty in the dump. The DVDs inside were in perfect conditions, however, and Sans couldn’t wait to watch them with Gaster. His reactions were the best. 

He’d already tossed the sullied outer casing, but it had pictures of five young humans, each with their own vibrant hair color and frilly costume. It looked cheerful and sweet, exactly the kind of thing his anime-loving boyfriend cooed over with the one of their coworkers, Alphys. Sans swiped the discs from the shelf near the television and put the first one into their makeshift disc player.

“So this is a new one?” He sounded excited, and understandably so. New stuff like this didn’t float down here too often, and, when it did, you had to beat someone else to it.

“Yup.” Sans answered simply and shuffled over to the couch once he had gotten the player going. The scene opened up to a girl running in a surprisingly creepy, mysterious world. Sans felt Gaster press a bit close to him as another girl soared toward some unseen figure. He guessed it was a bit spooky, though he welcomed any digression from sparkly joviality in an anime.

Once the scene mellowed out into a school setting and their pink-haired protagonist met up with her friends, Sans glanced over at his partner, who seemed thoroughly enraptured in the saccharine slice of anime life. He smiled a little, closed his eyes, and snuggled up to Gaster, it was nice to see him enjoying it, but this show wasn’t really Sans’ thing. Oh, the sacrifices he made.

After an hour of happiness, friendship, and just, costumed girls, Sans opened his eyes when Gaster gasped. And. Yikes. One of the main characters had just been offed by a strange, colorful snake monster (They were always the villains in human stuff). Gaster, like the two other girls on screen were still watching in horror, mouths agape, as another girl swept in and saved the day.

“Aw, man, I kinda liked that one,” Sans said, he’d been half listening to the show and the now dead crusader had been the only source of exposition in the series. He was more surprised that any death at all had occurred; shows like these always saw the heroines prevail, not… pre-fail. Ugh. This DVD had come to an end, so he had to get up to switch it out for the next one.

“Sans, that was awful! Oh my god, poor Mami-san. What will they do now?” He looked. Distraught. Which was kind of funny, but Sans patted him on the back anyway, because only Gaster would be so cute as to be genuinely saddened by the death of an anime girl.

“I think they’ll move on. Maybe one of them will take her place? Or that dark-haired girl’ll do it.” Sans said as he regained his position on the couch. The main girl’s friend was pledging something that sounded pretty righteous.

“You’re right, Sans. I’m sure it’ll get better.”

It did not get better.

First there was the red girl, Sans’ favorite, who swept in and kept the rash blue girl in line. It was a kindness, because he knew her violent, harsh attitude only stemmed from a desire to protect. Meanwhile the dark haired girl swept silently in between scenes and had thoroughly captured Gaster’s interest.

“I wonder why she acts like that?” Gaster had asked, apparently conjecturing, now. “She must be nice because she uses her powers to save everyone, but she’s so standoffish and mysterious. It’s almost suspicious.” 

Sans mumbled something noncommittal, he had no idea. The red girl and the rash girl were about to have their big fight as the protagonist watched on in fear. Sans payed attention halfheartedly - the fight scenes were kinda cool. He didn’t think he could do half so well in heels. The scene became more and more tense, before they were gifted with a terrible revelation. The thing that had turned them into costumed heroes… had been forcing their souls into containers outside of their bodies. Gaster seemed especially dismayed at that revelation. To permanently remove another’s soul… it was a scary idea. Souls were such private things. All the girls were as shaken as his boyfriend was.

Sans was kind of intrigued at this point and things began to become grimmer. One girl’s soul became corrupted and the red girl committed suicide to end her suffering. Gaster cried at her declarations of friendship and the implications of her love for the other. Now, there was also a looming threat on the horizon, an apocalyptic being would descend upon the girl’s town and kill everyone very soon if it wasn’t defeated. Then, there was the revelation that the dark-haired girl had been stuck in a time loop for years, trying again and again to save the town and her friends. Her dedication to the protagonist had seemed strange, but this explained it all. Sans couldn’t imagine having to repeat the same stretch of time over and over again, having to watch your loved ones dying over and over. He was surprised she wasn’t more unstable. He didn’t think he could be near so motivated after all that time. 

Gaster had cried when she had to go back in time, too. Sans hoped he wasn’t getting too upset at this.

“Hey, G, do you want to stop watching for now? We can pick it up later.” Sans offered. Gaster would be depressed for days over stuff like this. It had taken him two whole weeks to get over that movie about a human and his dog.

“No, it’s sad,” He sniffled, oh, dear, but straightened up, “But I need to know how it ends. I’m sure they’ll pull through.” Sans wasn’t so sure. He guessed he’d just give Gaster a hug after this and hope for the best. 

And so they watched. Long monologues and drawn out scenes reached a climax when their sweet main character martyred herself for the good of all others. She gave a tearful goodbye to the dark haired girl, and Gaster was crying in earnest as she bade her friend farewell. Even as the credits closed, his boyfriend was still sobbing. It did end well, even if it was a bit bittersweet.

“Sans… That was so beautiful,” he said as he rubbed at his eyes. Sans wrapped his arms tighter around his cute partner’s middle. He was too empathetic for his own good.

“Aw, Gaster. C’mere.” Gaster reciprocated his hug and nuzzled Sans’ head, still sniffling. They’d been sitting here for hours now and his warmth made Sans kinda drowsy. Even if it sounded a little weird, Gaster was really soft when he was relaxed.

**Notes for the Chapter:**

> this one is more romantic, ahhhh. please tell me if my summation of the show was confusing, so i can edit it!
> 
> btw, feel free to request like literally anything. though i did have a few ideas in mind hmmmmmmmm. whatchu think:
> 
> first date (my fave)  
> marriage  
> flirting  
> trophy wife sans (i saw a prompt and idc if it wasn't sanster in the end)  
> Soulmates/Soul bonding (i love)  
> someone at the office finds out about their scandalous relationship (0:)  
> assorted angst  
> jealousy (i love drama)  
> assorted gaster personalities (so many)


	3. First Date!

Sans was incredibly nervous. He’d been fantasizing about this date all week long and had just finished picking out a decent outfit. He’d been overjoyed at first, but as the days passed by, he’d begun to feel more and more anxious about it.He had scoured dating guides on the Undernet for advice and had made sure he followed what them, the decent ones at least, down to the smallest detail. His outfit was casual, though a bit neater than his usual wear, and he thought it looked pretty nice on him? The guides had said that nothing suited a monster better than the color of their magic, so he’d settled on one of the nicer blue sweaters he owned, forgoing his ever-stained hoodie. It had rarely been worn - mostly because it actually fit him and wasn’t oversized. He felt kinda shy… Normally, he avoided fitted clothing because of how small he was, but the guides had said that wearing ill-fitting clothing was impolite, or something, so he’d had to. He wanted to be a good date, after all.

He was fidgeting quite a bit, a big no-no in the world of dating, but he couldn’t help himself. Gaster would knock on the door any minute, and then they’d go eat at some local restaurant and it would hopefully go smoothly, but, oh, he was so nervous. He really did like, love even (but that was a secret for now), his co-worker, and, though it was kind of inappropriate, he, sweaty-palmed and hot in the face, had tentatively approached him a week ago to confess his feelings. Gaster and him had been friends for a long time and hung out quite a bit, so Sans had figured that, even if he was rejected, he would be let down gently. Surprisingly enough, Gaster had said he felt the same way, and had for a long time. He’d been just as shy about it as Sans was and Sans couldn’t help but to grin stupidly when he thought about it. He really had no reason to worry. But it was their first date!

They spent a lot of time together and their dynamic had always been very easy going, so there really shouldn’t be a problem. Though there was something about the formality of the occasion that made him feel shy. It wasn’t just a hang out session, it was. A Date. A date with the only monster he’s ever loved. And now they’re going to hang out. Romantically. 

He lamented over his nervousness for a while, and, eventually, he was saved from his self-torment by a knock at the door. It was time. Oh, no. Sans needed several more hours to mentally prepare himself for this. He shuffled to the door anyways. Opening it revealed his date (!!!) for the evening. 

“Hey, Sans,” Gaster said, glancing down at him. He was blushing, which was really cute and also really reassuring because Sans was blushing too.

“Heya.” Very natural. Very suave. “You look… nice,” Sans stated awkwardly. It was true, though. Gaster usually didn’t dress too casually, stuffy as he could be, so the longsleeve shirt and pants combo stood out. It looked like Gaster had followed the magic color rule, too. He wondered if Gaster had been on other dates before. Probably. Gaster was so likeable.

“Thank you? Oh.” Gaster looked at him, seemingly registering the nervous, sweaty puddle of a skeleton in front of him, before smiling knowingly. He laughed, ”You look nice, too. Wanna head out, Sans?”

Sans nodded, even more flustered now. He exited his apartment and locked the door, before turning around to face his now more-than-friend, who still looked as adorable as ever. A-door… -able. Yeah, he wasn’t going to say that one out loud.

As they started walking, Gaster started talking to him about something he’d recently watched and they fell into the rhythm of conversation easily. Sans was relieved, so far it seemed like dating wouldn’t be that different from their usual hanging out. Even if it was romantic. 

He felt his nervousness begin to subside; he really wasn’t sure why he’d been stressing over this. Being with Gaster was always the best because of how natural it felt. He felt a burst of confidence and decided that he’d try to be the suave date he’d fancied himself being in his daydreams. He walked a bit closer to Gaster, steeling his nerves, before reaching out and taking hold of his hand. Gaster tilted his head to peer curiously at Sans, who felt his blush return with a vengeance at the acknowledgement of what he’d just done. It was handholding - not a big deal. But it was also handholding with Gaster. Oh, angel.

Sans felt as if he should say something. Suave. Witty. Right, he could do this. “Looked like you needed a hand there, G. Heh.” Yeah. Sure. That worked.

Luckily, Gaster’s sense of humor was just as bad as his and his joke was well-received. “Oh, Sans,” he laughed. Sans grinned up at him. Yep. Suave, expert dater Sans achieved. 

Gaster’s hand was a warm and comforting weight in his and Sans was probably smiling like an idiot as they walked the rest of the way to the restaurant.

\---------------------------------------------------------------------------------

When they arrived, Sans let go of Gaster’s hand to open the door for him, as one of the dating guides had suggested.

“Thank you, Sans. I’m swooning,” Gaster joked, before stepping into the establishment and holding the door as Sans scrambled in in turn. Sans had been here before, but only a couple times. He preferred this one place out in Snowdin, Grillby’s, but that was too far out for either them to justify. This restaurant was nice inside; everything painted in subtle, calming shades. The food smelled good, too. 

As they settled down in a booth - it was a small place, so they didn’t have to wait to be served - Gaster began to speak. 

“You know, Sans, I was pretty nervous about this,” he said, sounding both lighthearted and shy and leaning forward so Sans could hear him, “Even though there wasn’t much reason to be. Didn’t stop me from languishing over it all week.”

Sans blinked at him and felt his smile widen. Gaster was so cute. “Aw, dude. I was pretty nervous, too. I haven’t actually gone on a date before.”

“Really? I haven’t either. I was worried my inexperience would make me a bad date.” Gaster noted, sounding somewhat surprised. 

“Hey, me too. Maybe if we’re both bad dates, it’ll cancel out into one good date, huh?” 

“Maybe, Sans,” Gaster looked more cheerful than before and Sans felt himself smiling, too. Knowing they were in the same situation made him feel much more relaxed. They probably looked really stupid, smiling like they were, but they continued to chat happily until a waitress appeared to ask them what they wanted.

Maybe this would be a good date, after all.

**Notes for the Chapter:**

> i tried. any feedback?
> 
> i'll probably do trophy waifu sans next, and then a soulmate chapter.

**Author's Note:**

> please tell me how i did! 
> 
> also this chapter may seem pretty platonic, but let me tell you it is written through the eyes of a shipper.
> 
> hit me up on tumblr! pixie-pier.tumblr.com


End file.
